Bonding joint for electric railways



(No ModeL) A.L.JOHNST'ON. BONDING JOINTS FOR ELECTRIC RAILWAYS.

-No. 523, 284. Patented July 17, 1894.

L v I W O 9' O 0 K L '0 0 0 Q a IFIIG3 INVENTOH WITNESSES flndmlrldimston Y ;g .z; b

Fries.

ANDREW LANGSTAFF JOHNSTON, Oli RICHMOND, VIRGINIA.

eoNoiNceo-iNT-FcRELECTRIC sAiLw/ws.

. srncxrr'oa'rxon forming part of Letters Patent No. 523,284, dated ul 17, Iss4.

Application filed May 5, 189 i; Serial No. 510,129- (No model.)

"To aZZ whoml it may concern:

Be it known that I, ANDREW LANGSTAFF JOHNSTON, acitizenof the United States, and aresident of Richmond, Virginia, have invented certain Improvements in Bonding Joints for Electric Railways, which the following-is a specification;

The object of my invention-is to make a simple and efiective bond connection for elec-' trically uniting two abutting rails by means of bonding wires; this object I attain in the following manner, referencejbeinghad to the accompanylng drawings, in which- Figural, is a sectional plan view of two abutting rails-showing the bond'in position. Fig. 2, is a side view of the abutting rails,

showingv the-holes prepared "to receive the bonds. Fig. 3, is an enlarged sectional view, showing the confining nuts. Fig. 4, is a detached perspective view of the nuts; and Fig.

5, is a sectional view of one of the nuts prior to its application to theibond.

Heretofore the method of bonding the rail joints of electric railways has been simply to 5 insert the wireinto ahole previouslydrilled .in the rail and then rivet the same thereto.

With this method, however, ithas'been found that thereis not enough electrical contact, it being a well known electrical law that all connections should have .at'leastten times the. amount of bearing surface as the area of the conductor.

The main feature, therefore, of my'invention consists in providing additional electrical contact for the bond by means of flanged confining nuts which embrace the end of 4 the bond andw'nich are screwed tight against the sides of the web of therail; the rail having been previously faced off so as to insure a close fit. I

In carrying out my invention 1 first ream the holes in each rail to a taper by means of aspecial tool, and then face-off each side of the rails around the holes so as to provide a smooth surface, against which the nuts can be screwed tight to afiord the proper contact.

I then take the wire bond A and bendit asshown in Figl1,and screwthread the ends a, and mount on these screw threaded ends the sleeve nuts B. one on each end, the exterior-surthe opposite face of the web of therail inthe present instance. By tightening nip on this nut G the-bonding wire is not only securely locked'to the sleeve nut B; but the nut O'is itself confined hardagainst the web of the rail and the conical portion of the nut B is forced into the tapered opening of the rail, thus insuring a perfectly tight joint.

To insure the nut C fitting tightly against the rail 1' preferably make it slightly concaved, as shown in Fig. 5,. so that as it is screwed onto the threaded portion of the bonding wireit will'have a tendency to cone fine the wire tighter than if, it were perfectly fiat.- r

The flanges-of each nut may be. square or hexagonal but I prefer to make them annular and provide them with recesses adapted to a" spanner, as shown .in Fig.' 4.

I claim asmy invention 1, The combination of the rail having a tapered perforation, with a bonding wire, a sleeve fitted to said wire, and adapted, to fit snugly in'the tapered perforation of the rail and having a flange bearing against one side Q of the rail, and a not adapted to bear against the opposite side of the rail, and to draw the tapered sleeve into the openingiin' the rail, the contact area of the connection being greater than the cross-sectional area of the bonding wire, substantially as described.

2. The combination of the rail, perforated to receive a bonding connection, a bonding wire, with a nut'adapted to the hole in the rail, said nut having a flange adapted to bear against the surface of the rail, substantially asdescribed. I

3. The combination in a rail bond, of a-wire having threaded ends, nuts B adapted to the threaded portion of said wire having a conical periphery adapted to a conical holein the rail and a flange adapted to bear against one side of the rail, with a confining not on the opposite side of the rail adapted to the proecting threaded portion of the bonding wire, substantially as described; r

4. A rail bond consisting of a wire having threaded ends, nuts B adapted to the threaded ends mounted on one side of the rail, and nuts 0 mounted on the opposite side of the rail, also adapted to the threaded ends of the bond, substantially as described.

'5. The combination of the bonding wire having threaded ends, the nuts B adapted to the thread ed portions of the same and having a conical periphery adapted to a conical openother side of the rail, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ANDREW LANGSTAFF JOHNSTON.

Witnesses:

MURRAY 0'. BOYER, Josnrr; I-I. KLEIN. 

